CNN also has learned that some leading Republicans want to expand the scope of any impeachment inquiry to include alleged 1996 campaign finance abuses and possibly other matters.

But several Democratic sources said House Democrats would fiercely oppose such a move -- and House Speaker Newt Gingrich is said to be adamant that any impeachment effort must have Democratic support to be credible.

Two Democratic sources who have been briefed on the materials accompanying the Starr report -- which were not publicly released with the report Friday but which have been made available to members of the Judiciary Committee and their staffs -- tell CNN that they contain no new blockbuster allegations.

But these sources say the materials contain additional graphic descriptions of sexual matters likely to embarrass President Bill Clinton. The sources also told CNN that there is a strong case made that the president committed perjury.

The information in the backup materials is also likely to call into question the president's denial that his relationship with Lewinsky fell under the definition of sexual relations he was given during his testimony in the Paula Jones sexual harassment suit, the Democratic sources said.

"Maybe the White House has an equally strong defense, but no judge would dismiss this case short of a trial," one of those sources said.

Liberals said to be fighting inquiry

However, Democratic congressional and party sources say liberals in the party are digging in their heels against any impeachment inquiry. Leading liberal House members want to drive an effort to drop an impeachment inquiry and instead draft a bipartisan resolution of reprimand or censure, according to several sources.

Republican leaders have opposed such a move, believing there is enough evidence in Starr's report to justify an impeachment inquiry.

A GOP source told CNN that while such sentiment could change based on what members heard from constituents in their districts this weekend, all expectations are that Republicans would push for an impeachment inquiry.

Gephardt, Daschle 'frustrated,' 'cautious'

On Monday, House Minority Leader Dick Gephardt (D-Mo.) and Senate Minority Leader Tom Daschle (D-S.D.) are scheduled to meet with Clinton during a campaign fund-raising swing in New York.

The two top Democrats in Congress talked Sunday evening, and two sources familiar with their conversation said neither was ready to rule out an impeachment inquiry. Both men were said to be frustrated with the legalistic argument by Clinton's lawyers that while the president might have been misleading and uncooperative in his testimony, he did not commit perjury.

Both Gephardt and Daschle are expected to issue statements Monday that fall far short of the White House wish that they put pressure on Republicans by saying an impeachment inquiry is unwarranted.

"They are going to be very cautious and perhaps a little critical," said a Senate source familiar with the two men's discussions. "They will not close the door on an inquiry. No way."